TRIBOLOGICAL INVESTIGATION OF BORON CARBIDE FILMS SLIDING AGAINST DIFFERENT MATING MATERIALS UNDER HIGH RELATIVE HUMIDITY

Abstract

Tribological performances are significantly affected by the tribo-chemical reaction of the mating materials, while the effect on the B₄C film under high relative humidity conditions are poorly investigated. Therefore, fiction tests of three tribo-pairs (B₄C/WC, B₄C/steel and B₄C/Al₂O₃) under 85% RH with various normal loads and sliding frequencies were performed. The results show that the B₄C/WC tribo-pair exhibits excellent tribological properties, including very stable friction curves, minimum friction coefficients & wear rates, maximum carrying-load capacity and the smallest fluctuations with the change of the normal load. Similar results have been obtained for the B₄C/WC tribo-pair with the increase in the sliding frequency. This is mainly attributed to the oxidation of WC to form WO₃ that is conducive in enhancing the tribological performances. Therefore, the sliding contact of B4₄C/WC is the desirable design for engineering applications under high relative humidity.

Keywords

• b₄c film
• friction and wear
• mating material
• normal load
• sliding frequency